The linear operating point of a transmitter used for satellite communications is typically determined by computing losses through an RF uplink path from a communications terminal transmitter to a gateway, and establishing an imprecise operating point through modulator level adjustment. The operating point is imprecise in that many factors are not easily measured at the communications terminal, e.g., due to radio gain variation, modulator gain variations, and imprecise measurement of the losses through the carrier chain. This imprecision in measuring an operating point usually results in either the transmitter being overdriven (which can cause interference and degraded performance) or underdriven, leaving unused link margin.